\documentclass{article}

\begin{document}
\title{how to learn latex}
\author{chilam}
\data{\today}
\maketitle{}

\begin{abstract}
  this is abstract
\end{abstract}


\section{learn from net}
\label{sec:instraction}

\subsection{aaaa}
\label{sec:instraction}

\subsection{bbbbb}
\label{sec:instraction}

\begin{itemize}
\item hel\verb|xx---1=d1laxtex|
\item hah
  \begin{itemize}
  \item nani 
  \item aaa
  \end{itemize}

\item haha
\end{itemize}

\begin{center}
  this will be center
\end{center}

\begin{tabular}[|]{|||}
  \hline{}
\end{tabular}

\end{document}
